Washington — This week's controversial American incursion into Pakistan is prompting new questions about whether the US must change its strategy in the war on terrorism and is putting the shaky US-Pakistan alliance under even greater pressure.

On Tuesday, the US dropped at least three precision bombs just inside Pakistan on the Afghanistan border, reportedly killing 11 people. US forces had been fighting a group of militants in Afghanistan's Kunar Province near the border, pursuing them when they fled into Pakistan, the Pentagon said. Pakistan's government strongly condemned the attack; the Pentagon maintained that the operation had been coordinated with the Pakistanis beforehand and that US forces had successfully targeted militants. But US officials left open the possibility that members of the Pakistani military were among those killed.

Complicating the picture were statements from the US State Department regretting the loss of life, suggesting the operation had occurred in error. Military officials were still investigating the incident on Thursday.

In some military circles, recognition is growing that security in Afghanistan is tied to Pakistan's ability to rein in militants within its own borders. Groups that have fomented unrest across the border continue to seek refuge inside Pakistan, they say. The NATO alliance has been limited in its response to the problem by its inability to take the fight across the border and inside a sovereign country that has been an important US ally.

American officials have been urging Pakistan to do it for them. But as Pakistan realigns itself under new political leadership, its government has approached the war on terrorism in its own way. Its motivations for containing violence in Pakistan are not necessarily aligned with the US desire to rid the region of violence coming from inside the border region, say analysts.

Moreover, not everyone believes Pakistan holds the key to security in Afghanistan in the first place.

US officials are wrong to blame Pakistan for instability and violence in Afghanistan, says Christine Fair, a senior political analyst at RAND Corp., a public policy group in Washington. Pakistan's border region, known as the Federally Administered Tribal Areas, will always be a sanctuary for terrorists that will want to target the US, she says, but to assign blame to Pakistan is to deny the real problem.

"It's become a bromide to externalize the failures in Afghanistan and blame them on Pakistan," says Ms. Fair. The US, she adds, must send a signal to Pakistan that it is serious about security by beefing up its own contribution of forces in Afghanistan. "It is a joke how few troops we have in Afghanistan," she says.

Currently about 60,000 forces are in Afghanistan, a combination of about 33,000 American and 28,000 non-US NATO forces. With its forces tied to the mission in Iraq, the US has resisted sending many more of its own troops to Afghanistan.

The US airstrikes come as the Pakistan government tries to reach peace accords with tribal leaders in a region in Pakistan along the Afghan border known as the Federally Administered Tribal Areas, home to many of the militant groups that have given refuge to the Taliban and other groups. American officials decry Pakistan's approach, in which the government has said it will negotiate with tribal leaders in an effott to bring peace to that region. The US, which does not support negotiating with terrorists, says such peace agreements are unenforceable and in the past have led to even more violence. Militants such as Baitullah Mehsud, suspected of assassinating former Pakistani Prime Minister Benazir Bhutto last year, operate in the region.

American military officials still aren't sure what to make of the incident until it is more thoroughly investigated. Adm. Mike Mullen, chairman of the Joint Chiefs of Staff at the Pentagon, told the Monitor the US and Pakistan have agreed to a joint investigation of the incident that will generate the information needed to better assess the situation for both sides.

"Based on the information we have, it is a very well-executed mission, well within the bounds of the rules of engagement. And in fact our forces were being fired on by forces across the border, and we responded," he says.

Earlier this week, Admiral Mullen had noted the importance of "strategic patience" when it comes to US impatience over Pakistan's approach, calling it "an enormously complex problem."

"There is a thirst to solve it overnight, but we're just not going to solve it overnight," he told defense reporters Tuesday.

Mullen, who has traveled to Pakistan three times since his appointment as Joint Chiefs chairman last fall, says he has struggled to find solutions to the problem and compares groups in tribal areas there with insurgencies in other parts of the world.

Mullen expects that any attack against the US will originate in the FATA region and recognizes the need to address the violence to bring security to Afghanistan. "At the same time, we cannot have Pakistanis who support insurgents coming across the border [into Afghanistan]. That is not going to be acceptable in the long run."

The uproar over the bombings points up the difficulty for the US and Pakistan as they attempt to unite against a common enemy. For internal political purposes, Pakistan's government must be perceived by its people as standing apart from the US. But in a fight in which public perception is as important as combat operations, the different approaches Islamabad and Washington are taking to the militants don't bode well for the alliance.

"It is good to show the Pakistanis that the US is serious when it comes to fighting terrorism," he says. "On the other hand, as you push Pakistanis to the corner to deliver more, you always have to draw a line on how far you can push."